Use Case is to be able to send a delayed reply to an InOut invocation. One example is BPEL receive and reply activities. In this example we need to send a reply after some time to the received invocation. Holding of the invoking thread till we can write the response is unacceptable.
In a scenario like above, we can store the incoming messagecontext to send the response later. But this causes the invoking thread to be returned. Returning of that thread causes the writing of an HTTP 200 OK to the outstream.
We can introduce a new switch, which can be set when we want to do the above scenario. Axsi2 transport module can send an HTTP 100 Continue to the client in the presence of that switch to let him know that we'll be sending the response later.